| Part One. Methods are developed to utilize DNA as an information-containing, structure-bearing material for the designed assembly of four-component structures. Specifically, building block materials are synthesized containing single stranded DNA as linker arm elements, and ruthenium trisbipyridine-type compounds are used as core complexes. This scheme incorporates derivatives of 3-bromo-[1,10]-phenanthroline and 3,8-dibromo-[1,10]-phenanthroline into DNA strands using phosphoramidite or H-phosphonate chemistries. Structural analyses of brominated phenanthrolines and ruthenium complexes of brominated phenanthroline are presented. Coordination complexes of ruthenium, containing zero to three bidentate ligands phenanthroline, 3-bromo-[1,10]-phenanthroline, or 3,8-dibromo-[1,10]-phenanthroline have been synthesized and studied using NMR, cyclic voltammetry, UV/visible absorbance and emission spectroscopy. The assembly of a four-component DNA nanoconstruction is studied by a combination of gel electrophoresis and mass spectral analysis.; Part Two. Artificial muscles made from Ionomeric Polymer-Metal Composites (IPMC) have been studied to elucidate the mechanism of electrogenerated bending actuation. Ionomeric polymers (Nafion117) and a series of IPMC materials prepared elsewhere have been studied in dry and hydrated forms of varying monocation counterions (H, Li, Na, K, Rb, Cs, Tl, TMA, TBA). The hydration and Young's modulus of each sample were determined. A model that relates the extent of hydration to the dry Young's modulus is presented in terms of osmotic forces. These investigations have proven useful for investigators of artificial muscle systems. Specifically, mechanisms of actuation account for osmotic and electrostatic bending forces. These results allowed direct observation of purely electrostatic bending in IPMC materials. |
